| Time Period | Minimum | 25th Percentile | Median | Average | 75th Percentile | Maximum | Standard Deviation |
|---|---|---|---|---|---|---|---|
| 2004-2008 | 0.65 | 0.74 | 0.77 | 0.78 | 0.82 | 0.99 | 0.06 |
| 2009-2013 | 0.76 | 0.86 | 0.90 | 0.92 | 0.97 | 1.25 | 0.09 |
| 2014-2018 | 1.00 | 1.18 | 1.29 | 1.34 | 1.42 | 2.31 | 0.22 |
| Total | 0.65 | 0.81 | 0.91 | 1.02 | 1.19 | 2.31 | 0.28 |